Step 6: Type cmospwd_win.exe /k if you want to erase your old BIOS password. The executable offers you following options:
1 – to erase Cmos,
2 – to erase Cmos, but try to preserve date and time,
0 – to cancel. If you absolutely don’t know your password, select 1 or 2, otherwise select 0.

Step 7: If you have any of the popular BIOSes listed in the cgsecurity.org/wiki/cmospwd page, you might try running just
cmospwd_win.exe
at the DOS box command prompt.
The utility will dump the most common places of your BIOS looking for your password.